Pipeline transportation of solid materials



specific illustration of one Patented Sept. 16 1952 UNITED PATEFN nameTRANSPO TATION OF soLfiJ MATERIALS 'Walter -Gro s: s; !r,, Kansas City,ill/ 61, assig nor to Kansas City Testing Laboratory; --Kansas City,M03, a corporation of Missouri 1N0 Drawing. Application February 13,1948,

Serial N0.;297. I9 claims. (01. 302mm This invention relates to methods"of transporting normally solid materials and, "in particular, refers totransportation bypip'eline. I p w p As is common knowledge, themostwidely used transportation media for large quantities of solid materialsare the railroad, thefship and the motor vehicle. In general,'theseimediajurnish an efiicient and inexpensiveiiiethod oftransportation. There are conditions, however, "to which such means oftransportation are not well adapted and wherein theiruse becomes iii' ficient and costly but of allproportion totlfe value of the material beingshipped, dipairtie ar in} dustry in which suchconditions are often'found is the mining industry. ,7

Many mines both old and new as ieic ateu 'isolatedregions which arempqssibie reach by ship and which are considerable distances,

often including rough terrain, from established rail and truck lines.The shipping of material from these mines by conventional means impliesa very large initial investment rolling stool: and a large regularoutlay to maintain and operate the equipment, In addition to thetransportation means itself, the investment stals'o provide forwarehouses, stockpilesloading' equipment, etc., since, unless 'thereisan excess or equipment, the shipping can only be do'n'e intermittentlyBecause these and many Dill Grills;- advantages of conventionaltransportation media greatly increase the cost of the mined products tothe consumer, the niarktaliility of many products is low in rela to thactualfv'alue "rodu'c'ts are and in many cases valuable e simplyabandoned at the .r'n'irle because transporf tation costs pricethenioutof themes 2A" a the aterials the U H tea Stats, carries a mini"uni freight hardener seven and a half s uare a tori, (It gene for perton.) Any reduction in the cost of trans porting potash would lower itspriceand directly aid the farming and 'agricultural indus'try andindirectly aid everyone the country; Iii the mining of potash near c-aastaa nav Mexico, sodium chloride (common tablesalfl is spy product.Because of the high c'os'to'f transpor tation 10,000 tons of thismaterial are abandoned daily since its ultimate consumer price won ,betoo high. A decrease in the costof transpo ting sodium chloride wouldmake it possible use a product now being abandoned and lower the cost ofan essential food item. 5 I

most valuable fertilizer Because of these andma :5 other instances ofexcessive costs due to mi's'applie'a'tion of conventional transportationmedia, it has" been a' principal object of my inventive efforts toreduce the cost of transporting soiubieimatena s' and materials whichare availablairi relatively small granules or particles. p

In order to reduce" transm ttance sgp'z gg materials of the typesmentioned, 'I incorporate manta I f eder;

than. the

is considerably less and for example, are also considerably less.Figures transportation Icosts of about 7 If solid materials are to besuccessfully transported by pipeline, they must, of course, be put intoa; fluid condition and. maintained in that condition until the point ofdelivery is reached. Solid materials may be put in a fluid condition bydissolving them ina suitablefiuidyniediuin or byjus fidine t em; influid medium having c it and d s p ve Set.- s a yi s'cou s' fiuid mediai transporting I articles; the present invention q hte n iat s the use fe1s1 or suspen idnspf the colloidal clays; especial aqueous colloidal"suspgn n 1 preferred form bf the invention a1 t e of colloidaleiayjisusfedwnicn has .0 1h" masse recofvierg o'r memesup ted;materi-als threfrom'.inayfb'e' easily and she ply accomplished bysuitable piste-sees such as ffil r'atio'n, I t'i'ofi and assessing;

In order-to descr be'n'iy invention mete sip cally, I shall new refertoseveral examp s there of which, it will be understood, aremer'iymtstrati've. I

Example-'1 According 'to 't his eir ample of the" invention a Wyomingtype bentonite clay parts (by weight) 6 Water parts 100 Granularmaterial (coal for example) parts When the clay and water in theseproportions are violently agitated together, a gel is formed having aStormer viscosity of about fifteen to twenty centipoises. The coalparticles may be added to this gel and the mixture forced by suitablemeans, mechanical means or by gravity, through the pipeline to thedesired point of delivery. The coal may be then separated from themixture by suitable means, filtration for instance, and, if desired,washed and dried, after which it is ready for marketin or use.

Insoluble solids are most suitable for the bentonite base transportingmedium since soluble materials, particularly the salts, have a tendencyto flocculate the clay. This is true of the gels formed by all of thecolloidal clay materials except that used in Example 2. This tendency toflocculation can be overcome to some degree, however, by carefuldispersion of the clays in fresh water followed by addition of thesoluble material which it is desired to transport. This material can, ofcourse, be subsequently recovered by evaporation or similar methods.

Other colloidal materials such as the Texa type bentonite clay may beused in this process and obviously many other materials, iron ore, forinstance, may be transported by means of the medium of this example.

Example 2 In this example a gel is used as both a dissolving andsuspending medium for the transportation of a single soluble material ora plurality of soluble or soluble and insoluble materials. A typicalmixture according to this example might be as follows:

Florida-Georgia type fullers earth parts (by weight) 6 Water parts 100(1) Potassium chloride parts (in solution) (2) Potassium chloride parts(in crystals)-- 35 The Florida-Georgia type fullers earth should containa substantial amount of its natural water of hydration. It is thencapable of forming a gel in salt solutions. At 70 F, a saturated watersolution of potassium chloride consists of thirtyfive parts of the saltand one hundred parts of water. Such a solution may be prepared and thesix parts of fullers earth added thereto.

When these ingredients are thoroughly mixed by suitable means, such asthe dispersion mill of Patent No. 2,044,757, a gel having a Stormerviscosity of about twenty centipoises is obtained. An additionalquantity of potassium chloride crystals, preferably of sufllcientfineness to pass a 100 mesh screen, equal to the amount in solution (35parts) may be added to this gel without appreciable settling. Thismixture of dissolved and suspended potassium chloride and a gel may thenbe forced through a pipeline to the desired destination.

At destination the solid crystals of potassium chloride may be filteredout, centrifuged, or separated by other suitable means from therepipeline.

maining colloidal salt solution. This operation may be facilitated bythe use of a thinning agent which may be sufficiently effective toreduce the viscosity to the point where the crystals will completelysettle out. Surface tension modifying agents, such as the sulfonatedalcohols, can also be added to facilitate separation of the granularmaterial. The dissolved salt may be recovered from the solution bysuitable methods of evaporation or precipitation.

The usefulness of the foregoing mixture may be increased still furtherby adding another material which can be dissolved in the solution of thepotassium chloride. Such a material is sodium chloride and thirtypartsof it may be dissolved in the saturated salt solution previouslydescribed. The dissolved sodium chloride and potassium chloride may beseparated from each other and from the solvent; by suitable methods atthe pipeline terminus.

The foregoing, mixture is of great practical value since sodium chlorideis a by-product in the winning of potassium chloride from sylvinitedeposits. Heretofore it has been abandoned because of high shippingcosts. It is now possible to transport it at virtually no cost since itcan be added with no liability to the transporting medium containing themined potassium chloride.

It will be noted that the fullers earth'of the type above described isparticularly valuable in regions where only mineral waters are availableas solvents. This clay readily forms gels in these Waters so that, eventhough an undesirable dissolved constituent is also transported, atransporting medium formed therewith will have sufllcient viscosity tocarry desired insoluble particles.

It will be clear that the specific ingredients, their proportions, andthe viscosities of the transporting media may very widely and must bedetermined in each case by simple "experiments or by the judgment of onepracticing the invention. If a normally solid material (or materials) isto be transported in the dissolved state the solubility at the lowesttemperature encountered en route should be taken into consideration,since an excess may be'precipitated and settle in the Solubility can beeasily determined from handbooks or simple tests. When a dissolvedmaterial is used, a trial analysis should be prepared on a test tubescale to make certain that it does not flocculate the colloidal gel. Asindicated, it is. desirable to use Florida-Georgia type fullers earthhaving a substantial amount of its natural water of hydration when adissolved material is transported because of its resistance toflocculation.

Certain properties of the suspended articles should also be taken intoconsideration before proceeding with full scale operations according tothe transporting method of my invention. These should be considered inconjunction with the viscosity and density of the liquid transportingmedium. It will be realized that both the density and viscosity of theliquid medium provide resistance to the settling of the suspended solidparticles. In general the density of the liquid medium or gel isincreased by the dissolved material to be transported, hence a gelhaving the desired amount of material in solution should be used in themaking of tests and decisions. If the solid particles to be transportedare less dense than this liquid medium, there is no problem of settlingand the transporting medium need not be viscous. This occurs onlyinunusual cases, however, and it is generally necessary to provide omegaviscous resistance to se' ling to supplement the or the conflictingconsiderations of suspending power and resistance to flow. Ihavelfoundithat the most desirable range of wi's'cos'i tyii'sffifteen totwenty centipoiss, as determined by the Stormer viscos'imeter, tho'ug'h:special considerations, especially pipe size, encounteredi'in'iparticular cases often make it desirable to use cos'ities outsideof thisrange.

The second factor which affects iviscous ares'lstanc'e'is the size andshape f the solid -particles. It is elementary that the "resistance tosettling is directly dependent on' the suri'acearea of the particles. Ingeneral, little control can be exercised over the *shape of theindividual :particle. When it can, the surface area :should be as largeas "possible in relation to (the particle's 'weight'or specific gravity.lfotal surface *area .is increasedibzl decreasing the size of ithe:individual particles. While particle shape control ma :not be alwayspossible, it usu'ally possible toifcon- "trol particle size to someextent by :mechanical or other means. This provides a convenient meansfor -controlling the viscous-rcsistancewhen a'specifiedviscosity isdesired.

The desired particle size, :shape and area as well as the viscosity ofthe I-iqu'id medium may be determined i arbitrarily or, preferably, bysimple tests. These tests consist merely in preparing a small sample ofthe viscous liquid medium, adding thereto some of *the solid particles,and observing the rate of settling of these particles. I prefer to havethe rate of settling ran within the range of zero to one foot per:minutethough it will "be understood that a greater rate of settlingmaybe tolerated iii the pipeline is short or if there iisjsufficientagitation within the pipeline to inhibit settling. If such tests showtoo great a rate of settling, the viscosity of the liquid medium may.be' increased though, as indicated above, when the viscosit is aboutfifteen to twenty .centipoises it is more desirable to decrease theparticle size -.or increase theindividual particle surface areas. If.such tests show a very low rate .of settling, it may be desirable todecrease the viscosity, by adding more solvent, and thus lowerresistance to flow through the pipeline.

These tests can obviously also be used to determine the proportion ofinsoluble ingredients relative to the other constituents of the fluidtransporting mixture.

In case it is not convenient "or possible to obtain a suitable rate ofsettling 'by controlling viscosity or particle surface area, agitationwith- :in the pipeline may be'employed. I prefer to do this by ridingthe inside of the pipessomewhat similarly to the way in which gunbarrels are rifled. When the fluid mixture passes through a rifled :pipeit is stirred so that the soli p ticles remain in suspension. Anothermeans of agitation consists in placing a device in the pipeline, atintervals, which scrapes the sides of the pipe and picks up anysettlin'gs. This type of '6 device used by pipeline companies to :cleantheir lines. I

When water is used as the solvent :and :dissolved materials aretransported, ithere is :of :course, likely to be a problem of corrosion.I ihav'e found that by adjusting the =pH= of the fluid mixture to 'eo,i: possible, that HO GDF-IGSiOH occurs in steel pipe of good grade. I-nca'se pH control is not satisfactory, the flpipes may, of course, @bemad'e of wrought onior lines with= gla'ss', rubben or other suitablnraterials.'

ln view'oi the;foregoing it vsii'lrbe r'ealiz'edthat sneer Lm'oresoluble materials and one or more insolublelmatenalsmaybe-simultaneouslytransported by any method at 'aicost which :may, in

many cases, be 1 considerably less than that :or

other m'etho'ds. It has Zbeen shown and S1'1'Oli1d now be apparent thatthe ipr'ecise details or method may be rather extensiveiy modihed so(that the scope or my 'inventi'onshould "be deter- -mined' by theclaims.a

ample 2 would be insoluble so far as I the claims are concerned since (1potassium zchloride "-fo-rmed asaturat'ed solution.-

1. The method-oi transporting granular materials i which: "comprisesmixing solidmaterials with a liquid and a colloidal clay capable offorming a gel with the liquid, forcing the mixture through a pipeline,and recovering the material from the mixture.

I 2. The method "of transporting soluble materials which comprisesmixing said materially-with a sol-verit therefor and a colloidal agen'tcapable of forming a gel with the solution'of material in solvent,forcing the mixture through a pipeline, and recovering the'mater'ial'from the mixture.

3. .The method of simultaneously transporting a soluble material and "aninsoluble granular-material which comprises mixing *said'materials'witha solvent for the soluble material and a cdlloidal -agent-capable.offorming a "gel with the solution of material and solvent, said :ge'l having suffic'ient viscosity to suspend thegramilar material,

forcing the mixture through a pipeline, and re- I covering the materialsfrom the mixture.

4. The method of transporting a granular insoluble material whichcomprises mixing said material with a liquid colloidal solution ofa-colloidal clay having suflicient-vls'oosity to "suspend the material,forcing the mixture through a pipelair-1e, and recovering the materialirom-tl-ie mixure.

'5. The method of transporting a granular insoluble material whichcomprisesmixing said material with a gel 'iformed by a-colloidal clayand solvent, said gel having su'fiie'ient viscosity to suspend thematerial so that it settles at a rate of substantially one foot perminute or less, forcing the mixture through a pipeline, *and reeoveringthe rn'aterialfrom 'the mixture.

6'. The" method oftransporting a granular insolublematerial whiehcomprises mming 's'aid material with a gel formed by a colloidal clayand solvent, said gel having a viscosity of from fifteen to twentycentipoises, said material consisting of granules having surface areassuch that their rate of settling is substantially one foot per minute orless, forcing the mixture through a pipeline, and recovering thematerial from the mixture, I

7. The method of transporting a granular material which comprises mixinggranules of the material having, substantially predetermined surfaceareas with a gel having a substantially predetermined viscosity formedby a colloidal clay and solvent, said surface areas and viscosity beingdetermined so that the granules have a substantially predetermined rateof settling through the gel, forcing the mixture of gel and granulesthrough a pipeline, and recovering the granules from the mixture.

8. The method of simultaneously transporting a soluble material and agranular insoluble material which comprises mixing said materials with asolvent for the soluble material and a colloidal clay capable of forminga gel with the solution of material and solvent, said gel having asufficient viscosity to suspend the insoluble material so that itsettles at a rate of substantially one foot per minute or less, forcingthe mixture through a pipeline, and recovering the materials from themixture.

9. The method of simultaneously transporting .a soluble material andgranules of insoluble material which comprises mixing said materialswith a solvent for the soluble material and a colloidal clay capable offorming a =gel:with the solution of material and solvent, the viscosityof said gel and the surface areas of said granules being such that therate of settling of the granules is substantially one foot per minute orless, forcing the mixture through a pipeline, and recovering materialsfrom the mixture.-

10. The method of simultaneously transporting a soluble material andgranules of insoluble material which comprises mixing said materialswith a solvent for the soluble material and a colloidal clay capable of"forming-a gel with the solution of material and solvent, said gelhaving a viscosity of fifteen to twenty centipoises, said granuleshaving surfaceareas such that their rate of settling in said gel issubstantially one foot per minute orless, forcing the mixture througha-pipeline, and recovering the materials from the mixture.

11. The method of transporting granular insoluble material whichcomprises mixing said material with a viscous liquid colloidal solutionof a colloidal clay, forcing the mixture through a pipeline, stirringthe mixture while it is in the pipeline, and recovering the materialfrom the mixture. V

12. The method of simultaneously transporting a water soluble materialand an insoluble granular material which comprises mixing the materialswith water and a colloidal clay capable of forming a gel with thesolution of soluble material and water, said gel having sufilcientviscosity to suspend the granules, adjusting the pH of the mixture tosubstantially neutral, forcing the-mixture through a pipeline, andrecovering the materials from the mixture.

13. The method of simultaneously transporting a water soluble materialand an insoluble granular material which comprises mixing the .materialswith water and a Florida-Georgia type fullers earth having a substantialamount of its natural water of hydration to form a gel of viscositysuificient to substantially support the insoluble material, forcing themixture through a pipeline, and recovering the materials from themixture. 7

14. The method of transporting a water soluble salt which comprisesmixing a Florida-Georgia type of fullers earth containing a substantialamount of its natural water of hydration with a water solution of thesalt to form a gel of predeterminedviscosity, forcing the mixture thusobtained through a pipeline, and recovering the salt from the mixture.

15. The method of transporting a water soluble salt which comprisesmixing a Florida-Georgia type of fullers earth containing a substantialamount of its natural water of hydration with a saturated water solutionof the salt to form a gel of predetermined viscosity, adding additionalparticles of the salt to the mixture thus formed of such surface areaand amount as to cause only inappreciable settling, forcing the mixturethrough a pipeline, and recovering the salt from the mixture.

16. The method of transporting water soluble salts. which comprisesmixing a Florida-Georgia type of fullers earth containing a substantialamount of its natural water of hydration with a water solution of thesalts to form a gel of predetermined viscosity, said solution beingsaturated with respect to at least one of the salts, adding additionalparticles of the saturated salt to the mixture, said particles being ofsuch surface area and in such amount as to cause settling at a rate ofsubstantially one foot per minute or less, forcing the mixture through apipeline, and recovering the salts from the mixture.

17. The method of claim 14 which includes the step of adjusting the pHof the mixture to sub stantially neutral.

18. The method of transporting particles of insoluble material by meansof a liquid medium of a liquid and colloidal clay having a predeterminedviscosity which comprises adjusting the particle size of the material sothat its rate of settlin in the mediumis substantially one foot perminute or less, mixing the material and medium, forcing the mixturethrough a pipeline, and recovering the insoluble material.

.19. The method'of transporting particles of insoluble material ofpredetermined size by means of a liquid medium of a, liquid andcolloidal clay which comprises adjusting the viscosity of the medium sothat the particles have a. maximum rate of settling of one foot perminute, mixing the material and medium, forcing the mixture through apipeline, and recovering the insoluble material.

WALTER M. CROSS, Jn.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,329,967 Greenstreet Feb. 3,1920 1,431,225 Greenstreet Oct. 10, 1922 2,042,423 Krekeler May 26, 19362,128,913 Burk Sept. 6, 1938 2,359,325 McConnell Oct. 3, 1944 FOREIGNPATENTS Number Country Date 334,060 Germany Mar. 27, 1919

1. THE METHOD OF TRANSPORTING GRANULAR MATERIALS WHICH COMPRISES MIXINGSAID MATERIALS WITH A LIQUID AND A COLLOIDAL CLAY CAPABLE OF FORMING AGEL WITH THE LIQUID, FORCING THE MIXTURE THROUGH A PIPELINE, ANDRECOVERING THE MATERIAL FROM THE MIXTURE.